Surfaces for axonal guidance are typically achieved in one of two ways. Chemical patterns of molecules that promote cell growth lead to good axonal guidance but are easily destroyed by non-specific protein adsorption. Topographical modification, on the other hand, is a more robust method but leads to a lower degree of axonal guidance.

In a recent article published in Nanotechnology, C Prinz et al. use rows of free-standing nanowires to guide peripheral nerve-cell axons with high fidelity. The nanowires are grown using MOVPE from EBL-defined gold nanoparticles on a gallium phosphide substrate. The distance between nanowires within a row is 400 nm and the distance between two rows is 10 µm. The axons follow the rows of nanowires with high precision and are unable to cross a row of nanowires, in sharp contrast to the situation when grooves are used to guide axons.

A strong interaction between the axons and the nanowires is evidenced by the internalization of the nanowires by the cells and by the localization of the focal adhesion points of the cells to the position of the individual nanowires.